air gun/airsoft/bb: you use it build up sight alignment/sight picture, trigger control, and follow thru.

Ditto for using laser system/MILES/etc.

Recoil: you can learn that via actual shooting. Recoil from compressed air gun and Simunition F/X is different from that of live firearm. Also, most military is moving away from heavy recoil caliber in pistol and rifle(not prone/mounted type).

Military/air gun: you must be talking about Quick Kill(QK)/Lucky McDaniel system using Daisy BB gun. Military eventually moved away from it to pop up/aimed shooting.

In Quick Kill, the trick was to hold the bore of the long gun below eye level, usually at shoulder height, but parallel to line of sight. You can apply the same principle to hip shooting.